Chromium is a miracle element when added to iron, combining with oxygen to form chromium oxide, the compound that prevents rust in stainless steels. The downside is that it also impedes bonding, making stainless difficult to weld. Using a flux can help by improving weld quality and allowing faster welding speeds.
Gas tungsten arc welding, a joining process developed decades ago, has been improved by many technology developments over the years, but the essentials are unchanged: It uses an electric arc between a nonconsumable tungsten electrode and the workpiece to produce a weld pool, and it uses a shielding gas. Experiments with brushing on or pasting on mixed metal oxide slurries have shown how this decades-old process can improve dramatically in penetration and speed.
September 1, 2009 | By Dr. Yehuda Baskin
Most tube and pipe producers weld the seam as it is—without additives or fillers—and risk the problems associated with oxidation. A specially formulated brazing flux, in liquid or paste form, dissolves and removes oxides, prevents re-oxidation, and helps transfer weld heat to the seam.